The present study focuses on the moderating role of school climate to promote students’ civic behaviors in their school. Following the Authoritative School Climate Theory, it is proposed that two key dimension of school social climate (student support and disciplinary structure) are relevant to explain students’ civic engagement within their schools. Using survey data from a representative sample of the Chilean student population (N,=,38,286 7th to 12th graders, 51.2% females, and 12.188 adults, 75% teachers and 25% school staff members from 754 schools) the present study tested the relative contribution of student support and disciplinary structure on students civic behaviors, directly and interacting with their sense of belonging. A series of two-level hierarchical linear modeling analyses revealed that, after controlling for sex, school phase, school size, and school administrative dependency, student sense of belonging was positively related to civic engagement within their schools. In addition, both student support and disciplinary structure (as reported by adults) showed a positive and direct effect on student civic engagement. However, a closer analysis of moderating effects revealed that only student support had an impact on the relationship between sense of belonging and civic behaviors of students within schools. These findings extend prior research on the association between sense of belonging and civic engagement by including the role of school climate, and in turn, inform the potential use of school-based efforts aimed at promoting adolescents civic engagement in middle and high school.